Search Results (5)

Lead (Pb) is one of the most relevant contaminants due to its high toxicity, even at low concentrations. The growing need for research about real-time Pb analysis in the field has driven advancements in portable, sensitive, and automated analytical methodologies. These innovations are crucial for taking proactive measures against the impacts of Pb pollution on ecosystems and public health. Flow analysis techniques have proven to be very effective in automating procedures for isolating and preconcentrating Pb in surface water and biological samples. Such automation boosts sample throughput and reduces processing time and reagent consumption, aligning with the green chemistry principles by lowering costs and minimizing waste. This review covers 31 recent automated analytical methodologies employing flow analysis techniques such as FIA, SIA, MSFIA, and LOV, emphasizing the trend toward portability and miniaturization, which facilitates in-situ analysis. Additionally, this review examines the pretreatment methods and detection systems used, highlighting the analytical parameters of each technique. The methodologies discussed demonstrate the capability to process up to 55 samples per hour accurately. Limits of quantification as low as 0.014 µg L⁻¹ are reported, enabling environmental monitoring that effectively detects Pb concentrations below the WHO and EPA drinking water reference values of 10 µg L⁻¹ and 15 µg L⁻¹, respectively. Full article

Manganese is considered an emerging pollutant and it is perceived as a potential threat to human health and aquatic ecosystems. The need to determine and monitor the presence of Mn in environmental water requires increasingly precise and accurate chemical analytical techniques that provide reliable information to take timely measures in the event of potential environmental contingencies. The automation by flow analysis technique has allowed analytical procedures to isolate and preconcentrate manganese in environmental water samples. Additionally, it brings forth benefits such as greatly enhancing the sample processing capacity and a reduced time and reagent usage, leading to cost savings and minimized waste production, thereby aligning with the principles of green chemistry. In this review, a recent report of some flow analysis techniques (FIA, rFIA, SIA, MSFIA, LOV, and MPFS) is presented, highlighting the trend of automation, whose portability and miniaturization allow for complete in situ analysis. There are two remarkable analytical features from the studies evaluated here, which are sample throughput and accuracy, with a maximum processing time of 120 samples h⁻¹ and an accuracy of 98%. The implementation of flow analysis techniques offers several advantages, such as miniaturization and portability. The discussed methodologies achieved limits of quantification as low as 0.26 µg L⁻¹, enabling environmental monitoring that can easily detect the reference value of 0.05 mg L⁻¹, established by the WHO and the EPA. Full article

A very simple, fast and non-chromatographic methodology for inorganic antimony speciation based on Multisyringe Flow Injection Analysis (MSFIA) employing online hydride generation (HG) ICP-MS was developed. The fully automated analysis is performed in two steps: firstly, Sb(III) is quantified by ICP-MS after chemical vapor generation; then, total antimony is determined in the presence of potassium iodide as a pre-reducer of Sb(V) to Sb(III). The Sb(V) concentration is quantified by the difference between the total antimony and Sb(III) concentrations, reaching an analysis frequency of 30 h⁻¹. The optimization was performed using a Box Behnken design. The MSFIA-HG-ICP-MS system allows the antimony speciation analysis with a detection limit of 0.016 µg L⁻¹ for Sb(III), working in a linear range of 0.053 to 5.0 µg L⁻¹. This method was applied for the determination of Sb(III) and Sb(V) in water samples from Maiorca Island, Spain, and the concentrations found varied from 0.10 to 0.14 µg L⁻¹ for Sb(III) and from 0.12 to 0.28 µg L⁻¹ for Sb(V). The results were validated by addition/recovery tests, obtaining recoveries between 90 and 111% in both cases. Furthermore, a good precision was achieved, 1.4% RSD, and sample and reagent consumption were reduced to a few mL, with the consequent decrease in waste generation. Thus, the proposed method is a good tool for the speciation of inorganic antimony at ultra-trace levels in waters, allowing its risk assessment. Full article

This paper presents the development and the application of a multisyringe flow injection analysis system for the fluorimetric determination of the major heat-stable known allergen in shrimp, rPen a 1 (tropomyosin). This muscle protein, made up of 284 amino acids, is the main allergen in crustaceans and can be hydrolyzed by microwave in hydrochloric acid medium to produce glutamic acid, the major amino acid in the protein. Glutamic acid can then be quantified specifically by thermal conversion into pyroglutamic acid followed by chemical derivatization of the pyroglutamic acid formed by an analytical protocol based on an OPA-NAC reagent. Pyroglutamic acid can thus be quantified between 1 and 100 µM in less than 15 min with a detection limit of 1.3 µM. The method has been validated by measurements on real samples demonstrating that the response increases with the increase in the tropomyosin content or with the increase in the mass of the shrimp sample. Full article

Some recent analytical sensors based on electrochemical and optical detectioncoupled with different flow techniques have been chosen in this overview. A briefdescription of fundamental concepts and applications of each flow technique, such as flowinjection analysis (FIA), sequential injection analysis (SIA), all injection analysis (AIA),batch injection analysis (BIA), multicommutated FIA (MCFIA), multisyringe FIA(MSFIA), and multipumped FIA (MPFIA) were reviewed. Full article